Saturday, 23rd September 2023

“Rose Periwinkle”; friendly plant

By Sereba Agiobu-Kemmer
13 August 2016   |   3:52 am
Rose Periwinkle, Pink periwinkle, Rosy periwinkle, Bright- Eyes, Cape periwinkle, Old- Maid, Madagascar periwinkle, Vinca are common names referring to the same plant. The botanical name is Catharathus roseus.

Rose Periwinkle, Pink periwinkle, Rosy periwinkle, Bright- Eyes, Cape periwinkle, Old- Maid, Madagascar periwinkle, Vinca are common names referring to the same plant. The botanical name is Catharathus roseus. Many do not know this important medicinal and ornamental plant because of its many common names which also applied to other species, causing confusion. Even the scientific name Catharanthus roseus, causes problems since the species used to be known as Vinca rosea or Vinca.

The rose periwinkle plant (Catharanthus roseus, Apocynaceae) is a native of the tropical rain forests of southeastern and eastern Madagascar and now grown ornamentally around the world. Few plants have generated as much recent interest among scientists and medical communities as the Madagascar periwinkle, Catharanthus roseus.

The traditional healers in Madagascar were using this medicinal plant for treating diabetes and blood circulatory disorders. This led to its study by western scientist who ‘discovered’ its anti-cancer properties. The anti-cancer properties have been recognized by the western pharmaceutical industry resulting in the production of two important medicines: vinblastine and vincristine currently used as medicine in chemotherapy treatments for childhood leukemia, Hodgkin’s disease, testicular cancer and cancerous tumors. Extracts of entire dried plant contain many alkaloids of medical use.

The principal alkaloid is vinblastine, or vincaleukoblastine (vinblastine sulphate), sold as Velban. The alkaloid has growth inhibiting effects on certain human tumours. Vinblastine is used experimentally for treatment of neoplasms, and is recommended for generalized Hodgkin’s disease and resistant choricarcinoma. Another pharmacologically important alkaloid is vincristine sulphate or vincristine, sold as Oncovin. Vincristine is used in treatment of leukaemia in children.

Using Vinblastine and vincristine in combination chemotherapy has resulted in 80% remission in cancers such as Hodgkin’s disease, 99% remission in acute lymphotic leukemia, 80% remission in Wilm’s tumour, 70% remission in gestational choricarinoma, and 50% remission in Burkitt’s lymphoma.

There are over 70 other alkaloids that have been isolated from the plant in addition to vilblastine and vincristine.

Extracts of Catharanthus roseus (or Madagascar periwinkle) have significant anti-cancer activity against numerous cell types. The greatest activity is seen against multi-drug resistant tumor types which suggest that there are compounds in the plant that are synergetic or additive with anti-neoplastic elements which helps inhibit resistance to these drugs. If this is not impressive enough, taken as a daily supplement, it is known to improve blood supply to the brain, increases oxygen and glucose for the brain to use, prevent abnormal coagulation of blood, and raises the brain levels of the neurotransmitter serotonin.

There are two classes of active components in the plant, alkaloids and tannins. One important alkaloids is vincamine. A closely related semi-synthetic derivative of vincamine widely used in medicine is known as ethyl-apovincaminate or vipocetine, blood thinning, and memory enhancing actions shown in double blind studies to help alleviate a type of dementia known as vascular dementia, in which the arteries supplying blood to the brain develop atherosclerotic plaques.

Further research is needed especially on bioactive compounds, means of preparation, and effectiveness of plants and herbal remedies.
Many agencies in the field of international intellectual property rights consider this development of Catharanthus roseus (Rose periwinkle, Madagascar periwinkle etc.) as a case of ‘biopiracy’.

The traditional native use of these plants has led to drug discovery without benefits to the natives who first used the plant. These medicines have proved very profitable for global drug companies, but virtually none of this money finds its way back to Madagascar, one of the poorest countries in the world. There are recent international agreements, which have tried to ensure that profits from the commercial development of animal and plant species return to the countries of origin. One of such agreement is the convention on biological diversity, which seeks the “fair and equitable sharing of the benefits from the use of genetic resources” together with the conservation of biological diversity and the sustainable use of its components.

Tropical rain forests contain scores of other plants that may also provide miraculous medical treatments. Yet scientist have tested less than one percent of rainforest plants. Many more rainforest plants could have treasures just waiting for scientists to produce new medicines that could give patients the miraculous healing they seek from a wide variety of afflictions. We simply do not know how many undiscovered plant species are being made extinct by fire, erosion and other forms of environmental degradation. About 50 percent of pharmaceutical drugs are derived from plants that, who knows, if another ‘Rose periwinkle’ is waiting in the rainforest of Madagascar or in Nigeria for that matter?

The lesson of the usefulness of this single, once obscure species should not be lost. Madagascar has an incredible number of unique plant and animal species that are becoming extinct at an astonishing rate, as Madagascar people level, natural vegetation to plant crops to feed an exploding population. Madagascar is one of the world’s poorest countries. While one can be sympathetic to their immediate food needs, there are probably many plants with potential medicinal, industrial, food or ornamental uses that will disappear before we learn their value. The tragedy of extinction is that each species is the product of millions of years of evolution that will never be duplicated.

Catharanthus roseus from its native tropical forest of Madagascar has found its way into gardens in many parts of the world, because of the interest in its landscape potentials. It is planted in the garden as a short-lived (annual), or long-lived (perennial) herbaceous plant or sub-shrub, where gardeners are not aware of its medicinal value. The hybridization of Catharanthus roseus with its rare wild relatives produced cultivars several times larger than the previous species.
As new cultivars are released regularly in exciting colors, in addition is the fact that the plant is low maintenance; requiring only basic care .It is essientially free of pests and diseases. These attributes make it a popular ornamental candidate for bedding; border, and container gardening.

It thrives well in hot and humid environments, but it tolerates the hot temperatures and also able to bear the extremes of drought and heavy rainfall. In temperate climate, it is best grown indoors or as an annual bedding plant. In warm climates, it develops a woody stem near the base and can get 0.6-1m (2-3 feet) tall and spread just as wide. As annuals, they are usually smaller and more postrate. Pinch back early in the season of growth to encourage branching and a fuller plant. The flowers drop off when they finish blooming, so no dead heading is needed.

Location: Catharanthus roseus should be planted in full sun or partial shade to promote flowers all year round. In hot climates, they do best with some shade at least some of the day. They start looking a little frazzled by the end of the day without some shade and tend to get somehow leggy when they get a lot of sun. A shady spot will promote lush foliage, but part sun seems to be their favorite spot, to obtain good foliage and plenty of blooms.

Catharanthus roseus can be propagated from tip cuttings as well as from seed, since plants grown this way will flower more profusely.

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